Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already provide readOnlyHint=true and idempotentHint=true. The description adds that the tool returns 'authoritative, up-to-date attributes' and instructs to 'Answer directly from the returned text content,' which gives behavioral context beyond the annotations. It doesn't cover error handling, but for a read-only fetch this is sufficient.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured with a purpose sentence followed by a 'WHEN TO USE' section. It is slightly verbose but every sentence carries useful guidance, including examples and an exclusion. The front-loaded purpose makes it easy to scan.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with two parameters and no output schema, the description provides complete context: what it returns (detail card with attributes and CTAs), when to use it, how to respond, and what to avoid. No missing information that an agent needs to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% for both sku and country, with each property having a clear description. The description reinforces that the SKU is for the exact product but does not add new meaning beyond the schema. Baseline 3 is appropriate given high coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Fetch a single product by SKU and render a detail card with full attributes' — a specific verb, resource, and output. It explicitly distinguishes this from search_fashion_products by noting it returns details for an exact SKU rather than a search.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The 'WHEN TO USE' section explicitly describes when to call (user asks for more info about a specific product already shown) and when not to (do not issue a follow-up search_fashion_products call). It provides concrete example phrasings and states the tool is authoritative, offering clear alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.